Speakers at the VoIPSA (VoIP Security Alliance) conference in Las Vegas warned that VoIP attacks are likely to increase. Methods of attack include DDoS (Distributed Denial of Service), caused by overloading a system - a common tactic for disrupting websites. Of course, there's are also the new vishing scams, which involve phishing using VoIP services.

During another Las Vegas conference, BlackHat 2006, Phil Zimmermann (creator of the PGP encryption tool) said that due to impending VoIP abuse, people are very interested in a secure VoIP client. Zimmermann has come up with such software, called Zfone.